β-lactoglobulin (BLG) is a whey carrier protein of 18.4 kDa. This protein is a good system for the preparation of micro- or nanoparticles for pharmaceutical industry because of its high solubility, safe status, biodegradable nature, gel forming ability, abundance, stability at acidic pH and against gastric pepsin. It has been shown that BLG can bind anticancer Pt-based drugs and that BLG–pectin nanoparticles can transfer cytotoxic Pt compounds to cancer cells.

To study the molecular basis of the Pt-based drug recognition by BLG, we have analyzed the interaction of this protein with two extensively used anticancer metallodrugs, i.e. cisplatin and oxaliplatin, both in solution and at solid state. Structural data reveal that cisplatin binds BLG coordinating Met7, His146 and Lys8 side chains, without affecting the overall 3D structure. The molecular structure of the adduct formed upon reaction of oxaliplatin with BLG suggests the existence of a single Pt binding site. Circular Dichroism analyses reveal that the overall structure of the protein is not altered upon interaction with the metal compound.

These results suggest that BLG could act as a carrier for anticancer metallodrugs and open the way for a rational design of new biomaterials based on metallodrug/β-lactoglobulin adduct nanoparticles.

Supramolecular protein assembly, such as cages, rings, and tubes can be used as reaction vessels and molecular templates for applications in catalysis, imaging and drug delivery.¹ Ferritin (Ft) is a member of ferroxidase family of enzymes that forms a spherical nanocage. It sequesters iron by concentrating it in its internal cavity for storage and detoxification.² Ft is very promising as a drug loading and releasing system since it is non-immunogenic, bio-compatible, highly stable, soluble in the bloodstream. It can be internalized via Ft-binding receptors (like transferrin receptor 1³ or Scara5⁴) that are over-expressed in a variety of malignant cells. Well established metallodrugs like cisplatin,⁵ carboplatin,⁶ a Pt-terpyridine compound,⁷ three different gold-based anticancer compounds (Auoxo3, Au2phen, Auoxo4),^8-9 a bimetallic Pt-Au compound¹⁰, a bimetallic Pt-As compound and a di-ruthenium complex¹¹ have been trapped within the Ft nanocages, taking advantage of the alkaline pH disassembly/reassembly protocol. The drug-loaded nanocomposites have been characterized by circular dichroism, to evaluate the protein secondary structure content upon drug encapsulation, and by UV-vis absorption spectroscopy, to assess the drug loading within the protein cage. ICP-MS allowed to quantify the amount of drug trapped inside the nanocage and to define metal/Ft stoichiometry, while X-ray crystallography unveiled the metallodrugs binding sites on the proteins structure and the nature of the interaction of the different compounds with Ft. The compounds often degrade upon encapsulation within the protein cage; metal-containing fragments coordinate Cys or His side chains. However, the coordination does not affect the overall cytotoxicity of the encapsulated anticancer agents, since many molecules of the metallodrugs remain trapped in the bulk within the inner core of the cage. Biological activity studies show that, even though the presence of the cage reduces the overall toxicity of the metallodrugs, the adducts of the selected compounds with Ft are generally more selective towards cancer cells than to non-malignant cells. Altogether these data indicate that encapsulation of metal-based drugs within Ft nanocages is a promising strategy to deliver these molecules to their final targets.¹²

1. Maity, B.et al. Curr. Opin. Chem. Biol. (2015) 25, 88.
2. Uchida M. et al. Am. Chem. Soc. (2006) 128, 16626.
3. Hogemann-Savellano, D. Neoplasia (2003) 5, 495.
4. Mendes-Jorge, L. PLoS One (2014) 9, 106974.
5. Pontillo, N. Commun. (Camb) (2016) 52, 4136.
6. Pontillo, N. ACS Med. Chem. Lett. (2017) 8, 433.
7. Ferraro, G. Nanomedicine (Lond.) (2018) 13, 2995.
8. Ferraro, G. Chem. Commun. (Camb) (2016) 52, 9518.
9. Monti, D.M. Dalt. Trans. (2017) 46, 15454.
10. Ferraro, G. Int J Biol Macromol. (2018) 115, 1116.
11. Petruk, G. Chem. Med. Chem. (2019) 14, 594.
12. Monti, D.M. Nanomedicine: N.B.M. (2019) 20 ,101997.

In December 2019, a novel strain of coronavirus, SARS-CoV-2, was identified. Infected patients revealed symptoms of fever, cough (dry), sore throat, and fatigue, which began manifesting after 5 days of incubation. Hoping to prevent transmission, many countries adopted a mandatory mask use in closed public spaces. However, most mask options display a passive action against COVID-19. To overcome such restrictions, this work proposes the incorporation of anti-viral essential oils (EOs) loaded onto a nanofibrous layer that can be adapted to both community and commercial masks.

Twenty EOs selected based on their antimicrobial nature were examined for the first time against the Escherichia virus MS2. The most effective were the lemongrass (LO), Niaouli (NO) and eucalyptus (ELO) with a minimum inhibitory concentration (MIC) of 356.0 mg/mL, 365.2 mg/mL and 586.0 mg/mL, respectively. Polycaprolactone (PCL) and cellulose acetate (CA) were prepared individually at 14 wt% in chloroform/dimethylformamide (DMF) and 10 wt% in acetone/DMF, respectively, and combined at 3:1 ratio. Polymeric solutions were then processed via eletrospinning with processing parameters being optimized to 24.7 kV, 3.2 mL/h and 21 cm. Uniform, beadless nanofibers were obtained. Mats were characterized as mechanically resilient, to endure movements arising from mask positioning, and hydrophobic in nature, to repel droplets coming from the exterior. Loading of the nanofibrous mats was accomplished via physisorption using the free -OH groups of the CA as linkers. Mats were loaded with the EOs at MIC concentration for 72 h (saturation). Presence of the EOs was confirmed along the mats. Antimicrobial testing via halo determination, verified their diffusion abilities. More importantly, time-kill kinetics testing of the loaded mats attested to the EOs capability to fight the virus MS2 even when bonded to the nanofibers. Data demonstrated the potential of these EOs-loaded PCL/CA nanofibers mats to work as COVID-19 active barriers for individual protection masks.

Pseudomonas aeruginosa is considered a pathogen with clinical relevance, due to its intrinsic antibiotic resistance. For this reason, it is crucial to think of alternatives to treat P. aeruginosa-derived infections. Essential oils (EOs), natural products, possessing anti-inflammatory, antiseptic and analgesic properties, have been applied in this aim. Yet due to their volatile nature, polymeric microcapsules are frequently engineered to incorporate the antimicrobial agents at the core and work as drug carriers. As the result, the microcapsules protect the antimicrobial agents from the surrounding environment and, consequently, prevent undesirable effects, such as early degradation. In this study, a delivery platform for a controlled release of cinnamon leaf oil (CLO) was developed, resorting to chitosan (CS)/tripolyphosphate (TPP) microcapsules embedded in a hydrogel-like matrix. CS microcapsules were produced without any pH adjustment (CS1) and with pH adjusted to 5.0 (CS4). Subsequently, the microcapsules were incorporated within sodium alginate (SA) and gelatin (GN) hydrogel-like films, prepared by the solvent casting-phase inversion method. SA and GN were selected since SA presents a fast ionic gelation with divalent cations and GN has a good biodegradability. Fourier-transform infrared spectroscopy analysis confirmed the effective incorporation of CS microcapsules with CLO within the SA/GN films. A continuous release of the entrapped CLO was achieved. In addition, a matched time kill kinetics against the bacteria was attained, and the SA/GN/CS1 films were determined more efficient. Data revelated the outstanding potential of CLO loaded films for the inhibition of P. aeruginosa.

BACKGROUND/AIM: Aberrant crypt foci (ACF) are early lesions in the neoplastic induction found in the rat colon of the carcinogenic model. ACF is one of the first changes in the colon that lead to colorectal cancer (CRC). Probiotics and fermented foods are well known for their beneficial role in gut health and previous studies showed their therapeutic effects on gastrointestinal diseases. The aim of this study is to investigate the preventive role of Propionibacterium freudenreichii and Faecalibacterium prausnitzii probiotics against CRC Induction in rats treated with azoxymethane (AOM).

METHODS: Rats were injected subcutaneously with 7mg/kg of AOM once a week for 3 weeks, and probiotics (P. freundreichii and F. prausnitzii) were administered orally at 1×10⁹ CFU/ml once a day for 6 weeks. 5- Fluorouracil (5-FU) as a reference anti-cancer drug was administered intraperitoneally at 35mg/kg 3 times a week for 6 weeks. After the treatment period, the colon of the rats was harvested and examined microscopically and histologically. Lipid peroxidation levels in colon tissues were measured using malondialdehyde (MDA) assay.

RESULT: Microscopical examination of harvested rat colons after methylene blue staining showed that the total number and multiplicity of ACF were significantly lower in the probiotics groups (p < 0.05) than the AOM control group that did not receive any intervention. Histological examination of the colon showed increased severe hyperplasia and dysplasia of the ACF in the AOM group compared to the treatment groups. Probiotics administration also reduced the levels of MDA in the colon of the rats compared to the rats in the AOM control group

CONCLUSION: These results suggest that probiotics play a preventive role in CRC initiation and development by slowing down ACF formation, reducing the severity of ACF lesions, and reducing lipid peroxidation levels in the colon.